Ophthalmic instrument



ug. 14, 1934. H. slMMERMAN OPHTHALMIC INSTRUMENT Filed Aug. 7, 1931v 3 Sheets-Sheet l ug- 14, 1934 H. slMMERMAN 1,970,150

OPHTHALMIC INSTRUMENT Filed Aug. 7, 1931 5 Sheets-Sheet 2 454oss3a25fo|sw910152925303540# AUS- 14, 1934 H. SIMMERMAN 1,970,150

OPHTHALMIC INSTRUMENT Filed Aug. '7, 1931 5 sheet-sheet 3 Patented Aug. 14, 1934 UNE STATES Parser OPHTHALMIC INSTRUMENT Application August 7, 1931, Serial No. 555,682

10 Claims.

My invention relates to ophthalmic instruments, and it relates more particularly to such an instrument of the tangent screen, type, for making investigations and tests of the retinal fields of a persons eyes.

In making a study of the retinal eld for diagnostic purposes, it is important that the patient be distracted as little as possible, as otherwise greater time will be consumed in making the tests, and the results may not be accurate.

The object of my invention is to provide a simple and efficient instrument of the tangent screen type, for the study of the retinal field, which is so constructed and arranged that, after the patients head is once properly positioned, all of the necessary adjustments and shifting of the screen, for the study of both eyes of the patient, will be made by the operator at the rear of the instrument, with a minimum of disturbance to the patient.

A further object of my invention is to provide, in such an instrument, an improved form of tangent screen whereby the making of the various tests will be greatly facilitated, and more accurate results obtained.

The nature and characteristic features of my invention will be more readily understood from the following description, taken in connection with the accompanying drawings forming part hereof, in which:

Figure 1 is a side elevation of an ophthalmic instrument embodying the main features of my present invention;

Fig. 2 is a top or plan view of the rear portion thereof;

Fig. 3 is a front elevation showing the tangent screen, the base frame being shown in section taken on the line 3-3 of Fig. 1.

Fig. 4 is a rear elevation of the instrument;

Fig. 5 is an enlarged central sectional view of the tangent screen, also showing the means for supporting and adjusting the same; and

Fig. 6 is a Vertical central sectional view of the front end of the instrument, illustrating means for raising and lowering the chin and brow rests.

It will, of course, be understood that the drawings and description herein contained are illustrative merely, and that various changes and modifications may be made in the structure disclosed without departing from the spirit of my invention.

Referring to the drawings,` in the particular embodiment of my invention therein shown, 10 is the base member, having a vertical standard 11 at the front end thereof. Slidably mounted (Cl. SiS-20) in the standard 11 is a vertical rod 12, having a bracket 13 secured at the upper end thereof, which serves to support a chin rest 14. The bracket 13, which carries the chin rest, also serves to support a brow rest 15, which is adjustably secured to said bracket 13 in any preferred manner, such for example as by means of thumb screws 16.

The lower end of the vertical rod l2 is slotted for the reception of one end of a lever 1 7, which 65 is pivoted by means of a pin 13 mounted in the base frame 10. The other end of the lever 1'? is engaged by the lower end of an adjusting screw 19, which is threaded in a portion of the base frame 10, the arrangement being such that when the adjusting screw 19 is manipulated, the vertical rod l2 and the chin and brow rests carried at the end thereof, may be raised and lowered.

'I'he rear end of the base frame 10 is provided with vertical standards 20, which serve to support upwardly extending vertical rods 2i.. The framework 22 is slidably mounted upon the Vertical rods 2l by means of projecting lugs 23. The lower end of the framework 22 is slotted for the reception of the front end of a lever 24, which is pivotally connected thereto by means of a pin 25.

The lever 24 is fuicrurned intermediate its ends, in the slotted upper end of a bracket 26 which is secured to the base member l0. The rear end of the lever 24 is engaged by the lower end of a thumb S5 screw 27, which is threaded in a bracket 28 secured to the rear end of the base member i0, the arrangement being such that when the thumb screw 27 is manipulated, the framework 22 will be raised and lowered vertically, being guided in its movements by the upwardly extending vertical rods 21, which are supported from the base member l0 in the manner hereinbefore described.

The framework 22 is also provided with forwardly extending lugs 29, in which horizontal rods 30 and 31 are slidably mounted. One of these rods 30 is provided with rack teeth 32 for engagement by a pinion 33, the shaft 3e of which is journaled in the framework 22.V The rear end of the shaft 34 is provided with a hand wheel 35. The 100 ends of the rods 3() and 3l are secured by means of brackets 36 to the rear face of the tangent lscreen 37. The foregoing arrangement is such that when the hand wheel 35 is manipulated to turn the pinion 33, the tangent screen 37 will be 105 moved from side to side to its desired adjusted position.

The tangent screen 37 comprises a plate .or board, the front face of which is a plane surface at right angles to the axial line extending from the eye of the patient. The front face of the tangent screen is graduated (see Fig. 3) by means of radial lines, preferably spaced at equal angular distances, and circular lines spaced apart a distance corresponding to the trigonometrical tangents of equal angles subtended from the point of location of the patients eye.

The outline of the tangent screen 37 is substantially elliptical, and this will be found in practice greatly to facilitate the usual tests vwhich are made by means of instruments of this general type, enabling the operator to manipulate the testing devices in front of the screen with a greater degree of accuracy, particularly when the same are used within the angles approaching the vertical.

Centrally located with respect to the tangent screen 37, and carried thereby, is a sighting tube 38, by means of which the operator may properly position the tangent screen with respect to the patients eye, in the manner to be hereinafter described.

A metallic strip 39 is secured to the rear face of the tangent screen 37, serving to stiffen the same, and the upper end of this metallic strip 39 is bent over, as at 40, forming a bracket for the support of a lamp 41, secured at the outer end of said curved extension. The lamp 4l serves to illuminate the working face of the tangent screen.

In the use of the instrument, the patient is placed with his chin resting upon the chin rest, and his brow bearing against the brow rest. In the initial positioning of the patient, the adjusting screw 16 may be manipulated to raise or lower the chin and brow rests, by means of the lever 17 which is pivotally mounted at the front end of the base member 1U. It may here be noted that the means for preliminarily adjusting the chin and brow rests are merely to insure a comfortable position of the patient, and this adjustment is not ordinarily changed after the same is once properly made.

The tangent screen 37 is now adjusted with respect to one eye of the patient. The manipulation of the hand wheel 35 serves to obtain a sidewise adjustment of the screen, by means of the pinion 33 and rack teeth 32 on the rod 30. The thumb screw 27 and lever 24, operatively connected to the framework 22, serve to obtain the vertical adjustment of the said screen. While the adjustments are being made, the operator sights the pupil of the eye through the sighting tube 38 which is mounted in the middle of the screen. After the adjustment is made with respect to the eye under test, the usual testing devices are manipulated in front of the screen, and the results noted in the customary manner.

After the tests are completed with respect to one eye, the screen is bodily shifted by manipulation of the hand wheel 35, without changing the position of the patient, until the pupil of the other eye is sighted, any slight vertical adjustments of the screen which may be necessary being made by means of the thumb screw 27 and its associated parts.

It will be noted that after the patients head is initially positioned with respect to the chin and brow rests, it is not necessary to disturb him again, all of the adjustments being made behind the screen. This results not only in a more expeditious examination of the patients eyes, but also in a greater accuracy of the determinations.

Furthermore, the elliptical outline of the tangent screen permits the operator to manipulate the testing devices in front of the screen with a greater degree of accuracy, particularly in that portion of the field which is near the vertical line passing through the axis.

I claim:

l. An instrument of the character described comprising means for supporting the head of the patient in a fixed position; a screen member having its front face arranged in the visual field of the patient and in a plane at right angles to the axial lines extending from the eyes of the patient; means for shifting said screen member sidewise to bring the center of said screen member alternatively into coincidence with each of the axial lines extending from the eyes of the patient; means for vertically adjusting said screen member; and means for mounting said screen member whereby the same may be shifted and adjusted as aforesaid.

2. An instrument of the character described comprising means for supporting the head of the patient in a fixed position; a screen member having its front face arranged in the visual field of the patient and in a plane at right angles to the axial lines extending from the eyes of the patient; means for shifting said screen member sidewise to bring the center of said screen member alternatively into coincidence with each of the axial lines extending from the eyes of the patient; means for vertically adjusting said screen member; a centrally disposed sighting tube carried by the screen member; and means for mounting said screen member whereby the same may be shifted and adjusted as aforesaid.

3. An instrument of the character described comprising means for supporting the head of the patient in a fixed position; a screen member having its front face arranged in the visual field of the patient and in a plane at right angles to the axial lines extending from the eyes of the patient,

the front face of said screen member being graduated by lines to define the various portions of the field; means for shifting said screen member sidewise to bring the center of said screen member alternatively into coincidence with each of the axial lines extending from the eyes of the patient; means for vertically adjusting said screen member; and means for mounting said screen member whereby the same may be shifted and adjusted as aforesaid.

4. An instrument of the character described 1 comprising means for supporting the head of the patient in a fixed position; a screen member havinfy its front face arranged in the visual field of the patient and in a plane at right anglesV to the axial lines extending from the eyes of the Y patient, the front face of said screen member being graduated by lines to define the various portions of the field; means for shifting said screen member sidewise to bring the center of said screen member alternatively into coincidence with each of the axial lines extending from the eyes of the patient; means for vertically adjusting said screen member; a centrally disposed sighting tube carried by the screen member; and means for mounting said screen member whereby the same may be shiftedy and adjusted asl aforesaid.

5. An instrument of the character described comprising means for supporting the head of the patient in a fixed position; a screen member having its front face arranged in the visual field of the patient and in a plane at right angles to the axial lines extending from the eyes of the patient, the'front face of saidscreen member lbeingV graduated by lines vto define the various portions of the field; means for shifting said screen member sidewise to bring the center of said screen member alternatively into coincidence with each of the axial lines extending from the eyes of the patient; a vertically movable framework supporting said screen member; means for vertically adjusting said framework; and means for mounting said screen member whereby the same may be shifted and adjusted as aforesaid.

6. An instrument of the character described comprising means for supporting the head of the patient in a fixed position; a screen member having its front face arranged in the visual field of the patient and in a plane at right angles to the axial lines extending from the eyes of the patient, the front face of said screen member being graduated by lines to define the various portions of the field; means for shifting said screen member sidewise to bring the center of said screen member alternatively into coincidence with each of the axial lines extending from the eyes of the patient; a vertically movable framework supporting said screen; means for vertically adjusting said framework; a centrally disposed sighting tube carried by the screen member; and means for mounting said screen member whereby the same may be shifted and adjusted as aforesaid.

7. An instrument of the character described comprising means for supporting the head of the patient in a xed position; a screen member having its front face arranged in a plane at right angles to the axial lines extending from the eyes of the patient, the front face of said screen member being graduated by lines to define the various portions of the field, horizontally arranged rods for supporting the screen member; means for shifting said screen member sidewise on said rods to bring the center of said screen member alternatively into coincidence with each of the axial lines extending from the eyes of the patient; a vertically movable framework having lugs in which said horizontal rods are slidably mounted; vertically disposed rods upon which said framework is slidably mounted; and means for vertically adjusting the framework on said rods.

8. An instrument of the character described comprising means for supporting the head of the patient in a iixed position; a screen member having its front face arranged in a plane at right angles to the axial lines extending from the eyes of the patient, the front face of said screen member being graduated by linesl to denne the various portions of the eld, horizontally arranged rods for supporting the screen member; means for shifting said screen member sidewise on said rods to bring the center of said screen member alternatively into coincidence with each of the axial lines extending from the eyes of the patient; a vertically movable framework having lugs in which said horizontal rods are slidably mounted; vertically disposed rods upon which said framework is slidably mounted; means for vertically adjusting the framework on said rods; and a centrally disposed sighting tube carried by the screen member.

9. An instrument of the character described comprising means for supporting the head of the patient in a fixed position; a screen member having its front face arranged in a plane at right angles to the axial line extending from the eye of the patient, the front face of said screen member being graduated by lines to define the various portions of the field; horizontally arranged rods for supporting the screen member; means for shifting said screen member sidewise comprising rack teeth on one of said horizontal rods, a pinion engaging said rack teeth, and a hand wheel for rotating said pinion; a vertically movable framework having lugs in which said horizontal rods are slidably mounted; vertically disposed rods upon which said framework is slidably mounted; and means for vertically adjusting the framework comprising a lever fulcrumed intermediate its ends and operatively connected at one end to said framework, and an adjusting screw engaging the other end of said lever.

l0. An instrument of the character described comprising means for supporting the head of the patient in a xed position; a screen member having its front face arranged in a plane at right angles to the axial line extending from the eye of the patient, the front face of said screen member being graduated by lines to define the various portions of the field; horizontally arranged rods for supporting the screen member; means for shifting said screen member sidewise comprising rack teeth on one of said horizontal rods, a pinion engaging said rack teeth, and a hand wheel for rotating said pinion; a vertically movable framework having lugs in which said horizontal rods are slidably mounted; vertically disposed rods upon which said framework is slidably mounted; means for vertically adjusting the framework comprising a lever fulcrumed. intermediate its ends and operatively connected at one end to said framework, and an adjusting screw engaging the other end of said lever; and a centrally disposed sighting tube carried by the screen member.

HAROLD SIMMERMAN. 

